A severe thunderstorm Monday morning left about 11,700 ComEd customers in DeKalb County without power.

Paul Callighan, ComED External Affairs manager, said the storm affected 12,500 customers total and would be a “multi-day restoration effort.”

As of Monday afternoon, four fire crews had been sent out to attend to power outages and fallen trees. The storm made its most significant impact on the Southwest side residential area of DeKalb, said DeKalb Fire Chief Bruce Harrison.

DeKalb Public Works worked to clear 12 obstructed roadways.

A portion of Normal Road was closed off after a tree fell in front of the house at 565 Normal Road. The tree hit an electrical line, and power was lost on the entire street around 7 a.m.

The damage created a necessary detour for residents of the house, said Andy Olsen, owner of the building.

“People had to find other ways to get out of the house,” Olsen said. “[They had to] walk through the backyards and stay off the street since they couldn’t use their cars.”

A tree also fell in the backyard, striking the detached garage of the same residence. Olsen said a car was in the garage when the tree fell, but he didn’t know if it was damaged.

“The fire department said we wouldn’t be able to go into the garage because of fear that it will collapse structurally,” he said. “So it kind of flattened the roof of it, and it looks like the garage is totaled.”

Olsen said residents of the house were well out of harm’s way and were able to find transportation to their respective places of work.

Pine Acres Retirement Home, located at 1212 S. Second St. in DeKalb was also affected. Harrison said the fire department kept watch on the building because it was running on emergency power and the roof air conditioners weren’t working.

Harrison said the fire department received 17 totals calls related to storm, two of which were related to emergency medical services.

NIU Meteorologist Gilbert Sebenste said the weather event was a line of severe thunderstorms, also known as a Squall line. The prolonged Squall line, also known as a derecho, caused “considerable damage over a large area.”

Sebenste said the weather station on the West side of the NIU campus recorded official wind speeds of 55 mph, but that area avoided the most damage.

“About a mile north of the university and a half mile south of the university, the winds picked up to 60 to 70 miles per hour and caused a lot of tree branch and tree damage,” he said.

Some corn crops were also hit hard.

“I can tell you based on the damage reports I’ve been getting that the corn has been pushed over or flattened all the way West and Southwest of Rochelle,” Sebenste said.

Harrison said although there was electrical and tree damage throughout DeKalb county, it could have been worse.

“We fared better than many communities,” he said. “There were a lot of places [more] affected than we were…You just have to let [the storm] come through and deal with the issues as they come.”

Callighan said areas north of DeKalb County, specifically Winnebago, Boone and McHenry Counties were “extremely hard hit” with more damages and more outages.

Sebenste said he elected not to venture outside while the storm was making its way through DeKalb County. He watched the 70-mph winds from inside his home.

“I literally looked out my window and saw a tree snap in half,” he said.

Editor’s Note: Managing editor Kyla Gardner contributed to this article.